title: Exposure prediction approaches used in air pollution epidemiology studies: key findings and future recommendations.
abstract: Many epidemiologic studies of the health effects of exposure to ambient air pollution use measurements from central-site monitors as their exposure estimate. However, measurements from central-site monitors may lack the spatial and temporal resolution required to capture exposure variability in a study population, thus resulting in exposure error and biased estimates. Articles in this dedicated issue examine various approaches to predict or assign exposures to ambient pollutants. These methods include combining existing central-site pollution measurements with local- and/or regional-scale air quality models to create new or "hybrid" models for pollutant exposure estimates and using exposure models to account for factors such as infiltration of pollutants indoors and human activity patterns. Key findings from these articles are summarized to provide lessons learned and recommendations for additional research on improving exposure estimation approaches for future epidemiological studies. In summary, when compared with use of central-site monitoring data, the enhanced spatial resolution of air quality or exposure models can have an impact on resultant health effect estimates, especially for pollutants derived from local sources such as traffic (e.g., EC, CO, and NO(x)). In addition, the optimal exposure estimation approach also depends upon the epidemiological study design. We recommend that future research develops pollutant-specific infiltration data (including for PM species) and improves existing data on human time-activity patterns and exposure to local source (e.g., traffic), in order to enhance human exposure modeling estimates. We also recommend comparing how various approaches to exposure estimation characterize relationships between multiple pollutants in time and space and investigating the impact of improved exposure estimates in chronic health studies.
authors.affiliation: National Exposure Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, USA.
authors.forename: Lisa K
authors.initials: LK
authors.lastname: Baxter
authors.forename: Kathie L
authors.initials: KL
authors.lastname: Dionisio
authors.forename: Janet
authors.initials: J
authors.lastname: Burke
authors.forename: Stefanie
authors.initials: S
authors.lastname: Ebelt Sarnat
authors.forename: Jeremy A
authors.initials: JA
authors.lastname: Sarnat
authors.forename: Natasha
authors.initials: N
authors.lastname: Hodas
authors.forename: David Q
authors.initials: DQ
authors.lastname: Rich
authors.forename: Barbara J
authors.initials: BJ
authors.lastname: Turpin
authors.forename: Rena R
authors.initials: RR
authors.lastname: Jones
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Mannshardt
authors.forename: Naresh
authors.initials: N
authors.lastname: Kumar
authors.forename: Sean D
authors.initials: SD
authors.lastname: Beevers
authors.forename: Halûk
authors.initials: H
authors.lastname: Özkaynak
mesh_terms: D000397:Air Pollution; D004781:Environmental Exposure; D004784:Environmental Monitoring; D016021:Epidemiologic Studies; D006801:Humans; D052638:Particulate Matter
chemical_list: D052638:Particulate Matter